Joint for use in scaffolding



p 20, 1956 G. B. A. YOUNG ETAL 3,273,921

JOINT FOR USE IN SCAFFOLDING Filed June 2, 1964 ofthe -T being bevelledat 45.

3,273,921 JlflllNT FUR USE llN SCAFFULDTNG George llternardl ArthurYoung, Lichiield, and Kenneth liohn Cadman, Sutton Coldtield, England,assignors to '5 Rapid Metal England Fiied June 2, 11964, Ser. No.$711,926 Cllaims priority, application Great Britain, June 4, i963,snare/as; Aug. 2, 1963, 22,116/63 3 tCiaims. (Cl. 287-535) EnvelopmentsLimited, Birmingham,

'- witha screw thread, a frustoconical or other tapering cam portion onthe rotatable member whichis engageable with a coacting part of the lugand a nut mounted on the bracket and engaged by said screw thread on therotatable memher, the arrangement being such that rotation of therotatable member in one direction causes said cam portion to I engagesaid enacting part of the lug to urge said surfaces on the lug and thebracket into 7 Reference will now be made to the accompanying drawingsin which FIGURE 1 is a side view of one example of a joint according tothe invention, and FIGURE 2 is a section on the line l -2 in FIGURE 1.

In the example shown in the drawings the joint includes a lug it) whichmay be secured (such as by welding) to a scaffold tube llll, or whichmay be formed integrally with a collar (not shown) carrying a plurality(e.g. four) of identical lugs. Each lug is of generally T-shapedcrossse'ctional configuration, the outer sides of the flanges The wcglfla of the T increases in width from one end of the lug iii to theother so that the planes of the flanges of the T are inclined to thelongitudinal axis of the tube to which the lug or lugs is or aresecured. At the smaller end of the web iltia the lug has a pair ofsupporting portions lltlc.

The joint also includes a bracket 12 of generally channel-shaped form,the web ll2a of the bracket being secured to one end of the scaffordtube 13 which it is required to connect to the lirst-mentioned tube ill.The two sides of the bracket are provided respectively with a pair ofinturned flanges 12b and the inner surfaces of these flanges engage theinner surfaces 1% of the flanges of the lug when the joint is assembled.The inner surfaces liii'b of the flanges of the lug lit? are not atright angles to the Web llila of the lug, but are inclined such that anacute angle greater than 45 is included between each surface 10b and theadjoining surface of the web tea. 'The inner surfaces of the flanges 12bare similarly inclined to the engagement.

sides of. the bracket 12.

The sides of the bracket 12 are formed respectively with a pair ofbores, of which one is of larger diameter than the other. Secured orformed over the outer end of the smaller bore is a nut 120 which coactswith the screw-threaded end of a rotatable member 1d. The opposite endof the rotatable member is a head of larger diameter than thescrew-threaded end and is provided with an eye Lida. The portion ll lbof the rotatable member Patented Sept. so, was

end is of frustoconical form of semivertical angle and acts as a camportion.

To join the two scaffold tubes together the bracket 12 is slipped overthe flanges of the lug so that the latter are disposed in the interiorof the bracket. The rota-table member lid is then turned so that the camportion 14b is drawn towards the nut and into engagement with thebevelled edges of the flanges of the lug 10. This causes the bracket tobe displaced laterally relative to the lug and the inner surfaces of theflanges on the lug l0 and the bracket 12 are drawn into clampingengagement. During tightening the bracket is supported by port-ions 10coflug 10. The inclination of the inner surfaces of the flanges 10bcauses the sides of the bracket 12 to be closed upon one another as thejoint is tightened using the rotatable member ll4l. I This ensures thatthe sidesof the bracket 12 do not spring apart in use when the joint isplaced under load.

In use the scaffold tube carrying the lugs is used as a 1 verticalmember in a scaffold structure and the flanges, of the lugs are inclinedupwardly and outwardly with respect to-the axis of the tube. Thepressure on the inner surfaces 10b of the flanges on the lug is thusincreased when any load is placed on the horizontal scaffold tubecarrying the bracket.

Having thus described our invention what we claim as new and desire tosecure by Letters Patent is:

*1. A joint for use in scaffolding comprising a bracket of channelshaped form having a web portion secured to one scaffold member, a pairof spaced side portions extending from said web portion, and a pair ofinturned flanges on edges of the side portions spaced from the webportion, said flanges having internal engaging surfaces directed towardsthe web portion; a rotatable member extending between said side portionsof the bracket at a position intermediate said inturned flanges and saidweb portion and comprising a screw-threaded portion engaged in a nutportion integrally formed on one of said side portions of the bracket,and an enlarged head projecting through a hole in the other of said sideportions and a frustoconical cam portion between the screw-threadedportion and the head and disposed between the side portions of thebracket; and a lug of T-shaped section comprising a web secured alongone edge to another scaffold member and a pair of flanges projecting inopposite directions from the web at an opposite edge thereof, saidflanges being bevelled along their external edges at an anglecorresponding to the angle of the frustoconical cam portion and havingtheir inner faces inclinedto the web of the lug at an acute anglegreater than the angle of said frustoconic-al cam portion, the engagingsurfaces of flanges on the bracket being inclined to the side portionsthereof at an equal angle and being engaged against the faces of theflanges on the lug adjacent the web thereof, and the cam portion of therotatable member being engaged against one of the bevelled edges of theflanges of the lug; and the joint being releasable by turning of therotatable member to displace the latter axially so as to permitdisengagement of the bracket from the lug.

2. A joint as claimed in claim 1 in which the width of the web of thelug increases from one end to the other so that the flanges thereof areinclined and the flanges of the bracketare correspondingly inclined tothe web portion of the bracket.

' 3 3. A ioim as claimed in claim 2 in which the lug is provided, at beand vat which -the web thereof is least wide, with a pair qf supportingportions adapted to engage and support the ends of the flanges on thebracket when the cam portion is glisengaged from the bevelled flange of'the leg. I I Memes Cited by the Examiner UNITED STATES PATENTS1,862,027 6/1932 Lord. 1.918.116 1/1933 Mansfield.

4 Pullman 285 -404 X Sargent 15141.7X Mudd. Libermont 287-103 FOREIGNPATENTS 5/1963 France.

Italy.

10 CARL W. TOMLIN, Primai-y Examiner. I T. A. LISLE, Assistant Examiner.

1. A JOINT FOR USE IN SCAFFOLDING COMPRISING A BRACKET OF CHANNEL SHAPEDFORM HAVING A WEB PORTION SECURED TO ONE SCAFFOLD MEMBER, A PAIR OFSPACED SIDE PORTIONS EXTENDING FROM SAID WEB PORTION, AND A PAIR OFINTURNED FLANGES ON EDGES OF THE SIDE PORTIONS SPACED FROM THE WEBPORTION, SAID FLANGES HAVING INTERNAL ENGAGING SURFACES DIRECTED TOWARDSTHE WEB PORTION; A ROTATABLE MEMBER EXTENDING BETWEEN SAID SIDE PORTIONSOF THE BRACKET AT A POSITION INTERMEDIATE SAID INTURNED FLANGES AND SAIDWEB PORTION AND COMPRISING A SCREW-THREADED PORTION ENGAGED IN A NUTPORTION INTEGRALLY FORMED ON ONE OF SAID SIDE PORTIONS OF THE BRACKET,AND AN ENLARGED HEAD PROJECTING THROUGH A HOLE IN THE OTHER OF SAID SIDEPORTIONS AND A FRUSTOCONICAL CAM PORTION BETWEEN THE SCREW-THREADEDPORTION AND THE HEAD AND DISPOSED BETWEEN THE SIDE PORTIONS OF THEBRACKET; AND A LUG OF T-SHAPED SECTION COMPRISING OF THE BRACKET; AND ALUG OF T-SHAPED SECTION COMMEMBER AND A PAIR OF FLANGES PROJECTING INOPPOSITE DIRECTIONS FROM THE WEB AT AN OPPOSITE EDGE THEREOF, SAIDFLANGES BEING BEVELLED ALONG THEIR EXTERNAL EDGES AT AN ANGLECORRESPONDING TO THE ANGLE OF THE FRUSTOCONICAL CAM PORTION AND HAVINGTHEIR INNER FACES INCLINED TO THE WEB OF THE LUG AT AN ACUTE ANGLEGREATER THAN THE ANGLE OF SAID FRUSTOCONICAL CAM PORTION, THE ENGAGINGSURFACES OF FLANGES ON THE BRACKET BEING INCLINED TO THE SIDE PORTIONSTHEREOF AT AN EQUAL ANGLE AND BEING ENGAGED AGAINST THE FACES OF THEFLANGES ON THE LUG ADJACENT THE WEB THEREOF, AND THE CAM PORTION OF THEROTATABLE MEMBER BEING ENGAGED AGAINST ONE OF THE BEVELLED EDGES OF THEFLANGES OF THE LUG; AND THE JOINT BEING RELEASABLE BY TURNING OF THEROTATABLE MEMBER TO DISPLACE THE LATTER AXIALLY SO AS TO PERMITDISENGAGEMENT OF THE BRACKET FROM THE LUG.